<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>Title</title>
  <style>
    body{
      height: 1000px;
    }
    div:nth-of-type(1){
      width: 100px;
      height: 100px;
      background-color: red;
      position: absolute;/*absolute 绝对定位*/
      right: 0;
      bottom: 0;
    }
    div:nth-of-type(2){
      width: 50px;
      height: 50px;
      background-color: #b3ff38;
      position: fixed;/*fixed 固定定位*/
      right: 0;
      bottom: 0;
    }
  </style>
</head>
<body>
<div>div1</div>
<div>div2</div>
</body>

</html>